"The MSS", from the abbey of Bec (Le Bec-Hellouin), written c. 1265-1272 is not strictly a missal, since it lacks an ordo missae and the canon, but in other respects it is close to a missale plenum in its contents, though it includes all the chants. It may have been a precentor's book, but equally well may have been designed for use of the altar.